
.boxx {
    position: relative;
    width: 400px;
    height: 400px;
    z-index: 1;
    display: flex;
    transition-property: transform;
    box-sizing: content-box
}

.big {
    width: 300px;
    height: 300px;
    position: absolute;
    top: 0;
    left: 300px;
    overflow: hidden;
    display: none;
}

.big img {
    position: absolute;

}

.mask {
    width: 100px;
    height: 100px;
    background: rgba(255, 255, 0, 0.4);
    position: absolute;
    top: 0px;
    left: 0px;
    cursor: move;
    display: none;
}

.small {
    position: relative;
}